This invention relates generally to conveyor systems, and in particular, to conveyor systems utilizing one or more conveyor lines, each of which is equipped with an alignment conveyor, or unscrambler, and a downstream process such as a sortation conveyor, or the like.
Many conveyor operations, especially those used in article distribution centers, receive a variety of articles varying in weight, height, length and depth. Normally, these articles arrive at the article distribution center via a truck or a train. The article distribution center is built having a plurality of separate unloading bays or docks, each of which provides an area for removing the articles from the truck or train and placing them onto a particular conveyor line. Many article distribution centers are constructed such that one end of the facility serves as an unloading end. Alternatively, an article distribution center may be constructed having a pair of opposing ends, each of which is formed with a plurality of unloading docks.
Each conveyor line of a conveyor system normally includes an alignment conveyor in operational connection with a sortation conveyor positioned downstream of the alignment conveyor. Once the articles are unloaded and placed upon a particular conveyor line, an input conveyor transports the articles to the alignment conveyor in random order and orientation. Upon reaching the alignment conveyor, clusters of articles are reoriented, or singulated, by the alignment conveyor to assume a single file or column. Upon singulation, the articles are forwarded to the sortation conveyor. In most applications, the sortation conveyor includes a scanner designed to read bar code information attached to an exterior surface of each article. The bar code contains information identifying the destination of the article. After scanning the articles, the sortation conveyor sorts the articles according to their destination and forwards the articles to one of a plurality of departure conveyors responsible for conveying the articles to their respective loading areas or docks. Once in the designated loading area, the articles are loaded into a train, truck or other form of transportation, and shipped to their final destination.
In article distribution centers having dual unloading ends, those articles which are not sorted by the sortation conveyor continue traveling along the conveyor line and are recirculated to the input end of the alignment conveyor on the opposing end of the article distribution center. Thus, in dual unloading end article distribution centers, each conveyor line forms an independent loop, composed of a pair of alignment conveyors located on opposing ends of the article distribution center. If only one end of the article distribution center acts as an input area for unloading articles, unsorted articles are recirculated along a recirculation conveyor to the input end of the original alignment conveyor.
A crucial aspect necessary for the efficient operation of an article distribution center that receives articles in random clusters is that the alignment conveyor in each conveyor line adequately singulate the articles, and minimize the occurrence of xe2x80x9cside-by-sidexe2x80x9d articles. xe2x80x9cSide-by-sidexe2x80x9d articles, as they are referred to in the industry, are two or more articles positioned laterally adjacent along the alignment conveyor, and remain so when discharged from the alignment conveyor. The presence of xe2x80x9cside-by-sidexe2x80x9d articles interferes with the proper scanning procedure of the sortation conveyor, due to the scanner""s inability to scan more than one article simultaneously.
Given the importance of adequately singulating articles prior to introduction to the sortation conveyor, the industry has advanced several alignment conveyors designed to minimize the occurrence of xe2x80x9cside-by-sidexe2x80x9d articles. One example of an effective alignment conveyor is disclosed in commonly assigned U.S. Pat. No. 5, 918,723, issued to Schuitema et al. This alignment conveyor addresses the problem of side by side articles by providing a recirculation assembly configured to recirculate unsingulated articles upstream to the input end of the alignment conveyor of the same conveyor line, thereby allowing clusters of articles to recirculate as individual articles are fed downstream.
One problem frequently encountered in article distribution centers occurs when a large number, or volume, of articles are being transported through the alignment conveyor of a particular conveyor line. If the alignment conveyor experiences a high volume of articles for a certain period of time, a bottleneck may form. This bottleneck may require the input conveyor of that conveyor line to be shut down until the bottleneck is cleared. Shutting down the input conveyor of a particular conveyor line reduces the throughput of the article distribution center.
An additional problem commonly encountered in article distribution centers occurs when a sortation conveyor is shut down for maintenance or due to a jam. As the article distribution center normally include a plurality of fixed docks or bays wherein the articles are unloaded onto one of the conveyor lines, in certain instances, articles already unloaded are being conveyed towards the alignment conveyor despite the sortation conveyor being offline. Also, articles may continue to be unloaded onto the conveyor line despite the temporary inoperability of the sortation conveyor, such as where the sortation conveyor is shut down due to a jam. Although an adjacent conveyor line may be experiencing low volume or no volume at all, the articles unloaded onto a particular conveyor line cannot be redistributed or diverted once placed upon the input conveyor. Consequently, these articles sit on the conveyor line until the sortation conveyor is brought online. As a result, a large volume of articles remain unprocessed until the maintenance is completed, or the problem with the sortation conveyor is remedied, thereby decreasing the efficiency of the article distribution center.
Consequently, there is a need for a conveyor system capable of effectively sharing the volume of articles between adjacent conveyor lines during peak volume periods or when the sortation conveyor is offline.
Accordingly, in one aspect, the present invention includes a conveyor system having at least one conveyor line equipped with an alignment conveyor. The alignment conveyor includes a first region configured to singulate articles and a second region configured to convey articles away from the first region. A first output conveyor extends from the first region, while a second output conveyor extends from the second region. Both the first and the second output conveyers convey articles downstream of the alignment conveyor. Providing a second output conveyor configured to accept overflow articles from the alignment conveyor during periods of high volume and transport those articles to a point downstream of the alignment conveyor results in a load sharing conveyor system capable of redirecting short term over capacity on the alignment conveyor. Reducing the over capacity experienced by a particular alignment conveyor increases the throughput of the conveyor system.
According to another aspect of the invention, a conveyor system includes a plurality of conveyor lines, at least one of which includes an alignment conveyor having a first region whereupon articles are singulated and a second region configured to convey articles away from the first region. An overflow handler is configured to receive articles from the second region of a conveyor line and transport the articles to an adjacent conveyor line. Conveying the overflow articles from one alignment conveyor to an adjacent conveyor line effectively shares the volume of articles among the conveyor lines. Sharing the volume of articles among a plurality of conveyor lines increases the throughput of the conveyor system by transferring unsingulated articles from a conveyor line experiencing peak volume flow to an adjacent conveyor line operating at less than capacity.
According to another aspect of the invention, a conveyor system includes a first and a second alignment conveyor, both of which include a first region in which articles are singulated and a second region configured to convey articles away from the first region. A sortation conveyor is positioned downstream of the second alignment conveyor. An overflow handler extends from the first alignment conveyor, and is configured to convey articles from the second region of the first alignment conveyor to the second alignment conveyor. Providing an overflow handler configured to convey overflow articles to an alignment conveyor of an adjacent conveyor line effectively shares the volume of articles between alignment conveyors.
According to still another aspect of the invention, a conveyor system includes at least one conveyor line with an alignment conveyor having a first region whereupon articles are singulated and a second region configured to convey articles away from the first region. A deflector assembly is provided which, when actuated, deflects articles away from the first region of the alignment conveyor. This deflector assembly permits articles to be deflected away from the first region when a downstream sortation conveyor is offline or jammed.
According to yet another aspect of the invention, a method for distributing a load of articles in a conveyor system includes singulating articles in a first region of an alignment conveyor, and conveying articles positioned in a second region of the alignment region downstream of the alignment conveyor. Conveying unsingulated articles downstream of the alignment conveyor enables the conveyor system to adequately process articles during periods of high volume by transporting the unsingulated articles to a region of the conveyor system where further processing may occur.
According to a further aspect of the invention, a method for redistributing articles in a conveyor system equipped with an alignment conveyor having a first region whereupon articles are singulated, and a second region configured to convey articles away from the first region includes deflecting articles away from the first region, and conveying articles from the second region of alignment conveyor downstream of the alignment region. Deflecting articles from the first region and conveying those articles downstream of the alignment conveyor permits articles to be efficiently processed in the event the sortation conveyor is offline or jammed.
The present invention facilitates high volume processing of articles by effectively conveying unsingulated articles from a conveyor line experiencing a high volume flow of articles to an adjacent conveyor line or other point downstream of the conveyor line, wherein the articles may be effectively and efficiently processed. This article volume sharing system distributes the articles within the conveyor system, and consequently, enhances the conveyor system""s performance and efficiency.
These and other objects, advantages and features of the present invention will become apparent upon review of the following specification in conjunction with the drawings.